New Libre 2 questions

So I noticed the Libre 2 is out now, maybe it’s been awhile but I’ve been aol so my wife sent it to me. It’s a bit confusing though, does it work just like the Dexcom now? Anyone using it? It says CGM then it says you can scan it.

Thoughts? I can’t wait for the new smaller Dexcom to come out.

  • A continuous glucose monitoring system FDA-cleared for adults and children with diabetes ages 4 years and above
  • Now with optional, real-time glucose alarms that notify you if you go too low or too high*
  • Unsurpassed 14 day accuracy1 for adults and children
  • Easily check your glucose levels with a painless2 one-second scan instead of a fingerstick†

*why do I scan it if it’s a CGM?

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Technically, it can be called a Cgm because it checks your glucose every 5 minutes, however, if you want to see the numbers you have to scan it, and scan it at least every 8 hours or the readings will not be able to be retrieved using their software. The major difference with libre2 are the alarms, which are very important to any type 1 diabetic…which is why there are many 3rd party devices and apps that allow you to see the readings without scanning… personally, its hard not to hack it if you’ve experienced the Dexcom or Medtronic…seems kind of lame without real time numbers for type 1 diabetics, but for many type 2 diabetics with hyperglycemic unawareness, the libre helps them a lot and they don’t mind that they have to scan


The alarm is a vibration of sensor. Not sure if there are different vibrations for high/low… But to see numbers, need to scan to know if action is required.
I’m not sure vibration would wake me during night.


I think it’s called a CGM because of the alarms, but to me that makes it more a CGM-FGM hybrid than a real CGM.


It’s actually sending a glucose value to the smartphone app every minute, and the app decides to raise an alarm. Modifying the app makes it possible to use the real-time values in XDrip:


So with a smartphone you can use it as a real CGM, but without it’s still an FGM?

It’s a real CGM if you use a modified version of the Android app. Officially, it’s FGM only. I suspect the scanning requirement has implications for regulatory approval. It’s a lot like the Libre 1 really, but you don’t need extra hardware.


The libre 2 will alert you with an optional noise alarm on the reader also, it does not give a reading, only alerts you when you are high or low…the smartphone apps work, but most do not work with smartwatches… maybe the blucon and applewatch…the miaomiao2 only works with xdrip, android 9, and android wear watches which makes it extremely difficult…most phones now ship with android 10 and automatically update… technically it does check your fluids every 5 minutes which is the reason they are allowed to call it a cgm, but realistically, you either have to use a 3rd party device, or use their reader


@kalle, are you using this without an add-on bluetooth transmitter (miaomiao, bluecon, etc)? If so, how close does your phone need to be to the sensor to pick up readings via NFC? (I understand I’d need to patch the librelink app as you describe).

I’ve been considering using the libre system for a long time, but have assumed I’d need to use an add-on bluetooth transmitter to make it work well.

As an aside, are there any US based users of Libre 2.0 on this board?

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That’s right, the Libre 2 communicates directly with my phone without using any external transmitter. It’s not using NFC either, though I can still scan if I want to. The Libre 2 has built-in Bluetooth. I haven’t tested the range specifically, but I’m sure it’s at least several meters. At home, it’s enough to have the phone in the same room. Outside, I just keep it in my pocket.

I’m only familiar with sensors on the European market. Is the 14-day US Libre actually referred to as the Libre 2?


Libre 2 having Bluetooth seems like a good improvement to me.

I think the US 14 day is the current version of libre 1. I think libre 2 is just barely entering the US market at this time, don’t know if it’s available in pharmacies yet or not.

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In the us, it is available, however it needs the reader, and will not communicate with any phones for now…I would not be surprised if we see the libre 3 before a phone/libre app works with it…most pharmacies have to order it, and the Dr. Prescription usually has to be very specific as many offices only have the 14 day libre 1 in their computer system

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Perhaps surprisingly, this seems to be covered by the European Software Directive in article 6 which was implemented in member states years back, which allows for decompilation of the code by a licensed user in order to enable interoperability with another application (xDrip in this case).

  1. The authorisation of the rightholder shall not be required where reproduction of the code and translation of its form within the meaning of points (a) and (b) of Article (1) are indispensable to obtain the information necessary to achieve the interoperability of an independently created computer program with other programs, provided that the following conditions are met:

(a) those acts are performed by the licensee or by another person having a right to use a copy of a program, or on their behalf by a person authorised to do so;

(b) the information necessary to achieve interoperability has not previously been readily available to the persons referred to in point (a); and

© those acts are confined to the parts of the original program which are necessary in order to achieve interoperability.

  1. The provisions of paragraph 1 shall not permit the information obtained through its application:

(a) to be used for goals other than to achieve the interoperability of the independently created computer program;

(b) to be given to others, except when necessary for the interoperability of the independently created computer program; or

© to be used for the development, production or marketing of a computer program substantially similar in its expression, or for any other act which infringes copyright.

This is why xdrip and libre 2 works in Europe and does not work in the u.s…we also can’t use xdrip with android 10 or 11, as the extra oop algorithm provided by miaomiao was based on android 9s libre link app…we are forced to carry around their libre 2 reader…probably because it is the same as the freestyle insulin x and freestyle neo plastic that was/is not popular in the u.s.


Hi, does anyone succeed with extending libre 2 to reuse it for another 14 days more, I wonder? Is someone working on that? I could not find any info on that case :cry: